Materials Data on LiFe2F7 by Materials Project

Abstract

LiFe2F7 crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional. Li1+ is bonded to four F1- atoms to form LiF4 tetrahedra that share corners with four FeF5 trigonal bipyramids. There are a spread of Li–F bond distances ranging from 1.90–1.92 Å. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to five F1- atoms to form FeF5 trigonal bipyramids that share corners with two equivalent LiF4 tetrahedra and corners with three equivalent FeF5 trigonal bipyramids. There are a spread of Fe–F bond distances ranging from 1.84–2.00 Å. In the second Fe3+ site, Fe3+ is bonded to five F1- atoms to form FeF5 trigonal bipyramids that share corners with two equivalent LiF4 tetrahedra and corners with three equivalent FeF5 trigonal bipyramids. There are a spread of Fe–F bond distances ranging from 1.85–2.05 Å. There are seven inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted bent 120 degrees geometry to two Fe3+ atoms. In the second F1- site, F1- is bonded in a bent 120 degrees geometry to two Fe3+ atoms. In the third F1- site, F1- is bonded in a distorted bent 120 degrees geometry to one Li1+ and one Fe3+ atom. In the fourth F1- site, F1- is bonded in a bent 150 degrees geometry to one Li1+ and one Fe3+ atom. In the fifth F1- site, F1- is bonded in a linear geometry to one Li1+ and one Fe3+ atom. In the sixth F1- site, F1- is bonded in a distorted bent 120 degrees geometry to one Li1+ and one Fe3+ atom. In the seventh F1- site, F1- is bonded in a bent 120 degrees geometry to two Fe3+ atoms.